What tool is suitable for unscrewing broken parts: how to unscrew a bolt with broken edges. How to unscrew a broken bolt? Effective ways to unscrew a broken bolt What to do if the trunk has cut off a bolt

When screwing in the bolts, it sometimes happens that the head breaks off. If such a problem occurs, of course, the question arises of how to unscrew the broken bolt without damaging the parts connected by it.

The simplest case is when a protruding part of the thread remains above the surface. This scenario is quite favorable. All you need to do is take it and, having adjusted it accordingly, carefully unscrew the rod. To facilitate the process, it is sometimes used. It is applied to the protruding part. Then they take a hammer and lightly hit the fragment with it several times. This will help the lubricant penetrate into the threads. Then they wait 5-10 minutes and begin to remove the rod.

It is more difficult to cope with such a task as unscrewing a broken bolt that is broken flush with the surface or even below it. The key will not help here, since there is simply nothing for them to grab onto. However, nothing is impossible, you just need to be patient. This problem can be solved in several ways. All of them are quite complex and time-consuming, but quite doable.

You can try to unscrew the broken bolt by making a groove for a screwdriver at the end of the rod. A deeper slot is made under the usual one. A Phillips screwdriver has a larger surface area for adhesion, so it is not necessary to deepen the groove particularly deeply. This method is quite effective and in most cases helps solve the problem.

However, sometimes the rod jams tightly, and a screwdriver does not help. For home handyman The question of how to unscrew a broken bolt still remains relevant. The most radical way is to drill a hole for the bolt in the rod smaller diameter and cut a thread in it. To do this you will need an electric drill with a set of drills. different diameters and a tap.

By screwing a small bolt into the fragment and applying it, you can easily deal with the problem. This method works in most cases. The only thing that is advisable to remember is that the thread inside the rod must be reversed. You need to drill the hole very carefully, exactly in the center. Otherwise, when unscrewing, the thread can easily be torn off.

A broken nail, screw or pin is removed in the same way. Bolt or other fastener easily come to the surface. In the most extreme case, the hole is gradually widened, using drills of different diameters (from smaller to larger) until the steel walls of the rod become very thin. After this, they can be broken and pulled out with tweezers.

There is another fairly simple way to unscrew a broken bolt with a recessed rod. You just need to weld the fragment using a nut. Its diameter must be at least 1 mm greater than the diameter of the rod. It is necessary that it warms up well and expands in time. The resulting node is watered cold water. After everything has cooled down, carefully unscrew the fragment.

We hope you have received the answer to the question of how to unscrew a broken bolt. We wish that in the future all bolts, screws and studs can be easily screwed in and out without breaking.

If you, by virtue of your profession or hobby, are engaged in repairing equipment, you are often faced with the question: - how to unscrew a broken bolt, part of which is in your hands, and the other remains in the thread?

In this article we will do short review ways to solve this problem. The choice of method is up to you, since everyone’s skills and available “arsenal” are different. Shall we begin?!

Let's look at how to remove a broken bolt from a thread using an extractor

For those who don’t know, there are external and internal extractors. If the bolt is broken in such a way that it is impossible to “grab” it, then the internal extractor may be the only solution to the problem.

The internal extractor resembles a tap. The shank (non-working part) is made “square” for tools.

Based on the type of working part, extractors are divided into wedge-shaped, rod and screw (spiral).

The working part of the wedge-shaped extractor has the shape of a cone with edges; the cross-section of the rod is the same along the entire length.

The screw extractor is a cone with a thread of left or right rotation.

The operating procedure is as follows:

When starting work directly on the car, make sure that the repair site is accessible for a drill, screwdriver, etc. Well, if the question is how to remove a broken bolt from a wheel hub, the repair area is open. But if you can’t “get to” the part, don’t be lazy and carry out the necessary disassembly, that is, dismantling everything in in this case unnecessary.

If you don’t know how to unscrew a broken aluminum bolt, using an extractor will be the best solution.

It is better to buy extractors in “extended” sets, i.e. complete with drills and guide bushings for them.

But, unfortunately, such a tool is not always available at the moment or it cannot be used due to the design of a particular unit.

If you have problems with torn edges, we recommend choosing fasteners best quality: https://avselectro-msk.ru/catalog/4976-bolty - bolts of suitable quality that can be purchased in any quantity.

Alternative ways to unscrew a bolt with torn edges

Welding a nut as a way to unscrew a bolt without edges

This old, tried-and-true method has brought many people out of a dead end during repairs.

Specific case. The bolt securing the front suspension arm on an old Suzuki Ignis broke. Moreover, the distance between the eyes of the lever bracket did not allow either hammering or screwing the extractor into the fragment. Welding in this case turns out to be the most effective means unscrew the broken bolt.

The essence of the technique is as follows.

We select a nut of a suitable diameter, put it on the broken bolt and weld it. If the bolt breaks flush with the surface of the part, fix the nut as accurately as possible in the center of the bolt. Let's cook. Carefully, without jerking, unscrew the broken bolt by the nut.

Disconnect the battery terminals! Ensure the safety of wiring, hoses, plastic products from melting and burning!

Let's say that the extractor and welding are not available to you. Then, if the bolt breaks in the thread, we use

Drilling is an excellent opportunity to tighten a bolt without edges

First of all, let's calculate the diameter of the drill. The formula for standard threads is simple - subtract the thread pitch from the diameter of the bolt (threaded part).

Next important point- how to avoid the drill being pulled to the side? To prevent such a nuisance, there are conductors. A conductor (simplified) is a plate with holes. Guide bushings (sleeves) corresponding to the diameter of the drill are fixed perpendicularly in the holes. The jig is fixed to the part, the sleeves are aligned with the holes with broken bolts. You can drill! It is the sleeve that will prevent the drill from deflecting.

The jig is indispensable if it is necessary to remove a broken bolt from aluminum part. Especially if it is the engine cylinder head.

You can also combine drilling with knocking out the remains of the broken bolt using a drift.

This technique is used if the threaded holes are through. Starting with a drill of the smallest diameter, we drill out the fragment. When the “wall” has weakened enough, we remove it with a drift. Then we clean the threads with a tap.

In this way, you can, for example, get rid of fragments of the studs securing the exhaust pipe to the exhaust manifold on a VAZ2114-15 without removing the latter from the engine.

Heating to remove a bolt with stripped edges

Let's consider this situation - there are no extractors, welding, conductor and good drills. How to remove a bolt if it is broken?

The problem can be solved (and sometimes very successfully) by heating the parts red-hot. After cooling, they will become more pliable and can easily be unscrewed with a chisel, center punch, etc. The described methods for unscrewing broken bolts are not an exhaustive, universal answer to problems of this kind. For clarity, watch the material in the video.

Thank you for your attention!

Personally, I have repeatedly encountered the problem when a bolt or stud breaks at the root. Moreover, I am not some kind of auto mechanic or mechanic. I say all this to mean that this quite happens with an ordinary person, who periodically deals with technology or other technical parts.
Well, since you find yourself in such a situation, then don’t despair - everything can be fixed. I offer you seven ways to get out of this situation and free the thread from a broken pin or bolt.

Preparation before turning out the fragment

But don’t rush to start unscrewing right away. Before doing this, you need to take steps that will make your efforts easier.
First of all, spray the broken area with penetrating lubricant. This can be any “liquid key”, WD-40. Let's wait a little.

Next, to relieve some internal tension, gas burner Let's thoroughly warm up the fragment and the area around it.

Well, then let’s move directly to unscrewing the broken pin or bolt.

Method 1: Flat head screwdriver and hammer

This is the easiest way, but it is not always suitable. In about half the cases, the pin breaks off with a fragment sticking out, which is just where you can get caught.

We take a flat-head screwdriver, press it against the fragment and, using impact movements at an angle in the direction of unscrewing the thread, carefully turn the fragment.

This method is suitable if it does not require much effort to unscrew. If the effort is not enough, then move on to the second method.

Method two: try to unscrew it with a chisel

This method is similar to the first one, but instead of a screwdriver we take a chisel. In the same way, we rest against the splinter and use percussive movements to turn it out.

A chisel makes it possible to create more force compared to a screwdriver.

Third method: core and hammer

If the bolt fragment does not have splinters, or even the breakage occurred just below the final surface of the thread, then you can try using a core.

We rest the core against the surface of the fragment with an offset and, with blows at an angle, we turn it out until the fragment can be hooked with pliers or another tool.

Fourth method: weld the nut by welding

In my opinion this is the most effective and quick option, but if you have welding machine. Its essence is to weld a nut onto a piece of bolt on top.
So, to do this, take a nut, but not the same size, but a couple of units larger. That is, if the broken bolt was 10, then take a nut 12. This is necessary for a better and larger welding site.

Holding the nut with pliers, we place it on the fragment, but not in the center, but offset. Using an electrode, we weld the stud and nut to one side inside the nut.
Then, after cooling, unscrew it with a regular wrench.

Fifth method: unscrew the pin with an extractor

Here you will also need a specialized tool specifically designed for unscrewing broken studs and bolts - an extractor.

We center the pin so that the drill does not run around when starting to drill.

Drill a hole of the appropriate diameter for the extractor.

We insert the extractor into the hole and unscrew it with a key.

Sixth method: drill out the fragment

The method is to select a drill according to the lower diameter of the stud thread and drill it out. A very difficult method that requires skill.
First we go through a drill of a smaller diameter.

Then we drill as close as possible.

We knock out the fragments and remnants of the stud with a flat screwdriver.

This method of removal is not always worth the effort, but it deserves your attention.

Seventh method: drill a clean hole and make an insert

The most time-consuming and expensive method of all. But there are times when this is the only working option to return the node to working condition.
We drill out the stud cleanly along with the thread.

We cut a new thread with a tap.

You can finish here if the design now allows you to select a thicker bolt or stud. If not, we buy an insert or order it from a familiar locksmith.
Lubricate the external thread with thread locker and screw it in.

Stitch flush.
What method did you use? Write in the comments, I think your experience will be interesting! All the best!

The node has been restored.

Among detachable connections, threaded ones take first place both in terms of prevalence and reliability. However, in practice there are many cases when it is not easy to unscrew a threaded pair.

Reasons why it is not possible to unscrew a stuck nut (bolt).

There are several reasons why disassembling this simple connection may be difficult or even impossible:

• deformation of the thread or connection parts, for example, due to a strong impact;
• screwing not according to the thread with the application of significant force - in this case, friction between the surfaces of the parts increases significantly (the effect can be aggravated due to the influence of external factors);
• oxidation of the surfaces of connection parts, formation of a layer of rust on them;
• diffusion of materials between joint parts.

The last two reasons are well known to almost everyone, especially motorists.

The problem is that studs, bolts and nuts are most often made of carbon steel. With prolonged contact with water and atmospheric oxygen (for example, wheel bolts are constantly exposed to this effect), these substances penetrate into the smallest gaps, including between the parts of the threaded connection. As a result, the iron oxidizes and a layer of rust forms, which increases friction. It will take a huge amount of force to move the parts out of place (often the magnitude exceeds the strength of the bolt, and it collapses).

Designers try to prevent such troubles by using parts with protective coatings or made of stainless steels. But this doesn’t always work. If the bolt and nut are exposed to heat (an example would be parts on a muffler) protective coatings may be disrupted, corrosion processes accelerate.

There is also a process of diffusion (mutual penetration) of materials; the parts form a monolith, which becomes difficult to disassemble (those who try to unscrew a bolt on the crankshaft often encounter this phenomenon).

How to unscrew a stuck bolt (nut) - basic methods.

To cope with this task, several methods are used. They can be roughly divided into

• mechanical;
• physical;
• chemical.

Mechanical methods.

These include methods that allow you to disassemble a threaded connection by applying mechanical forces:

• the use of ring wrenches and socket heads instead of open-end wrenches;
• using leverage to increase effort;
• impact with variable direction of force;
• accentuated impact (short-term application of significant force or forces at certain points);
• impact destruction of layers of oxides and rust.

An open-end wrench covers only three edges of the nut or bolt head. In addition, there remains some gap between it and the edges. In this case, applying sufficient force to unscrew it may be a problem - the key may break off and “lick” the edges. Spanner or socket head cover all edges, which allows you to apply more force.

To increase the force, you can use a lever to increase the length of the handle. In this case, there remains a danger of licking the edges or destroying the fastening parts. You can also damage those parts that were connected by a threaded pair.

Often, changing the direction helps to unscrew a stuck or rusted nut - before unscrewing the connection, try to screw it in. The impact of forces alternately in different directions destroys the layers of rust, allowing the connection parts to move.

An example of the application of significant force for a short time is provided by the method using a chisel and hammer. They make a notch on the edge, place a chisel against it (directing it as the nut is unscrewed) and hit it with a hammer. In this case, the impact force is much greater than what can be applied using wrench. Since the impact is short-term, it cannot destroy the bolt.

For your information! This method can also be used to unscrew a nut with torn edges. This is somewhat easier than trying to cut new ones to fit a smaller key size.

Lightly tapping a nut and/or bolt with a hammer causes the entire structure to shake and destroy the rust layer. You only have to dose the impact force so as not to damage the parts or deform the thread. Although one of the methods for disassembling a “recalcitrant” connection is destroying the nut with such blows. The only problem is that the threaded pair will have to be changed.

Physical methods.

Some of them are based on physical properties metals Of these, only one is widely used - heating the connection parts. At the same time, the material of the nut expands, the gap between it and the bolt increases, and it becomes easier to unscrew it. If you heat up the entire structure, you can destroy the formed rust, which will also give positive result. For this purpose, you should use any heat source - a powerful soldering iron, construction hairdryer, blowtorch or other open flame sources.

Important! Using an open flame near wood, flammable plastic or flammable liquids is dangerous!

Electric heating is a good replacement for open fire. For this, a transformer (factory or homemade) with a secondary winding with a voltage of 1.1 - 1.5 V and maximum current is suitable. Through copper cables and clamps, the secondary winding is connected to a bolt that must be unscrewed. Warming up occurs, after which the transformer is turned off and the connection is dismantled.

Other physical methods use the method of wetting surfaces to reduce friction. For example, if you allow liquid to penetrate the space between a bolt and a nut through the smallest channels, the friction between the threads will decrease and the pair will become easier to disassemble.

Of the easily penetrating liquids, you can use those that are always at hand for the motorist:

• brake fluid;
• antifreeze;
• kerosene;
• gasoline;
• diesel fuel.

The first two contain glycols and ethers - substances with enormous penetrating power. The rest are aliphatic hydrocarbons and have a similar effect.

The second group also includes solvents such as white sprit and turpentine. All of them can be used to unscrew a stuck nut. The processes differ somewhat only in time.

The method is simple - wet a rag and place it on the stuck parts. Penetrating into the gaps and pores, liquids lubricate surfaces and loosen layers of rust. After some time (from half an hour to 3-4 hours), you can try to unwind the connection. If disassembly fails, repeat the process. You can speed it up by periodically light tapping.

These same liquids are the basis for “liquid keys” - lubricants of a special composition that are offered in car dealerships.

One of the most popular among car enthusiasts is WD-40, which contains mineral oil, white spirit and gasoline of highly volatile fractions. The effectiveness of this “cocktail” has been tested in practice; it can remove rusted nuts in half an hour.

For your information! If the nut becomes stuck not due to water contact, but under the influence of temperatures, the effectiveness of WD-40 is significantly reduced.

Chemical methods.

Their action is based on the chemical destruction of rust formed between the connection parts. To do this, it is necessary that active chemicals get into the gaps between the bolt and nut.

Used for such processing threaded connections almost any acids:

• sulfur;
• salt;
• vinegar;
• lemon;
• orthophosphorus, etc.

Sulfuric acid for battery electrolyte or hydrochloric acid for soldering radiators is used in this way:

• a rim is arranged around the nut or bolt head made of plasticine;
• A few drops of acid are added inside the resulting “container”;
• a piece of zinc activates the process, creating a galvanic couple.

A day after the start of such treatment, any connection unwinds.

Weaker acids are less effective and require either a significant amount or more time.

For your information! Phosphoric acid is found in drinks such as Coca-Cola. That is why you can try to unscrew the nut with their help. But its concentration is low, the acid itself has low activity, so this treatment is effective only in “mild” cases.

If all else fails.

If you still fail to unscrew the nut, the connection can be destroyed by cutting it off with a grinder.

Another method is to drill out the bolt with a drill.

But before resorting to such methods, you should evaluate all the consequences!

Video.

Good advice and useful trick How to shorten a bolt, stud or screw. The fact is that if you cut the threads in the usual way, you will no longer be able to screw the nut back onto the threads. All this happens due to the fact that the threaded turns are wrinkled.

There is a simple way out to avoid this.

Will need

• A bolt, stud or screw that needs to be cut and shortened.
• Nut, 1-2 pcs., with the same thread.

Cutting a bolt, stud or screw correctly

So I'll take a screw as an example. Use a marker to mark the place for the cut. We measure with a ruler.

Screw 1-2 nuts onto the bolt beyond the mark. In general, the nuts should be on the side that you will need later.

Now let's cut it off. Depending on the thickness, this can be done in several ways:

• Bite off with nippers.
• Cut with a grinder.
• Saw off with a hacksaw.
• Clamp it into a screwdriver and rotate the bolt and cut it off with a hacksaw.
• Or another way.

It's not important for you to choose.

I bit it off with wire cutters because the screw is thin. Of course, this is the crudest method, but it is fast.

Now hold the nut with pliers and use a screwdriver to remove the screw. This is the trick: after unscrewing, the nut will straighten all the threads at the tip of the cut.

It is better to screw on two nuts; they will better correct the entire thread.

Now, you can easily screw nuts onto this cut screw.
This is how you can easily preserve all the working properties of a bolt, stud or screw after cutting.